2 REVIEW OF THE LITERATURE
2.5 Surgical treatment of humeral shaft fractures
Surgical treatment of humeral shaft fractures has been suggested in several clinical situations (Table 1). The indications are derived from retrospective case series. There are no studies validating the superiority of surgical care over nonsurgical treatment in these situations, but a common sense justifies an operative approach. According to current literature, the most common associated injury, primary radial nerve palsy (PRNP) with no other indication for surgery, is generally not considered an indication for early nerve exploration (Böstman et al. 1986, Shao et al. 2005, Ekholm et al. 2008b, Heckler et al. 2008, Liu et al. 2012, Korompilias et al. 2013). However, the most recent systematic review combining 58 observational studies with 890/7262 PRNPs found that patients with early exploration had a higher chance of nerve recovery than those with late exploration (89.8% vs. 68.1%) (Ilyas et al. 2020). This conclusion can be criticized for overestimating the effect of early exploration. Some of the patients with early exploration could have recovered without intervention, but the patients with late exploration do not include those with spontaneous nerve recovery. There are no RCTs comparing surgery with nonsurgical care in humeral shaft fractures complicated with PRNP.
Table 1. Generally accepted indications for surgical treatment of humeral shaft fractures.
Clinical situation References Bilateral fracture Brug et al. 1994
Pathological fractures Flinkkilä et al. 1998, Laitinen et al. 2011 Floating elbow (arm and
forearm fracture)
Rogers et al. 1984, Sarmiento et al. 2001
Multiple trauma patient Bell et al. 1985, Brumback et al. 1986 Brachial plexus or artery injury Gainor et al. 1986, Brien et al. 1990 Open fractures (grade II or III) Brug et al. 1994, Sarmiento et al. 2001
Symptomatic nonunion Campbell 1937, Barquet et al. 1989, Jupiter et al. 1998
2.5.1 OPEN REDUCTION AND PLATE OSTEOSYNTHESIS
Originally, the aim of ORIF was to anatomically reduce the fracture by exposing the fracture site, compressing the fracture either with an interfragmentary lag screw or by using dynamic compression with the plate (Müller 1963). Compression is appropriate especially in simple fractures and has been shown to improve bony union (King 1957). However, in comminuted fractures, compression of the fracture is not possible. This led to the concept of bridge plating, where the alignment of the bone is corrected without interfering with the fracture zone and fixing the plate from both sides of the fracture (Heitemeyer et al. 1987).
The plate is fixed with locking or nonlocking screws according to the surgeon’s preference and quality of the bone (Fig. 13). Often use of locking screws is recommended in osteoporotic bone with three bicortical screws on both sides of the fracture (Gautier et al. 2003). However, in a cadaveric study of osteoporotic bone, addition of a third locking screw did not strengthen the construction (Hak et al. 2010). In a biomechanical study with a bone model, the construction with two locking screws on both sides of the fracture gap showed similar biomechanical properties in an osteoporotic model compared with three nonlocking screws on both sides of the 1 cm fracture gap (Grawe et al. 2012). In the same study with a good-quality bone model, the construction with three nonlocking screws was slightly superior to that of two locking screws. These findings have not been validated in vivo.
The length of the plate is often debated. There is no good evidence for an optimal plate length. Empirically, in comminuted fractures, a plate length of 2 to 3 times and in simple fractures 8 to 10 times the length of the fracture zone has been suggested (Gautier et al. 2003).
A potential benefit of plate fixation of the humeral shaft fracture is that it seems safe to use the extremity for weight-bearing, as this did not increase the number of hardware failures, malunions, or nonunions compared with patients not bearing weight with upper extremity (Tingstad et al. 2000). This has clinical implications in patients with multiple injuries who have an injured lower extremity in conjunction with a humeral shaft fracture. It enables ambulation by using crutches even when weight-bearing of the lower limb is not permitted. Also, patients depending on the use of canes or other walking aids can remain ambulatory after fractured humerus.
Fig. 13.
A. A 62-year-old woman fractured her left humeral shaft (AO/OTA 12A3b) due to a fall from a standing height.
B. The patient was randomized to surgery. The fracture was reduced through an anterolateral approach and fixed with a locking compression plate using dynamic compression.
C. The fracture healed uneventfully, and a strong fracture union was observed at 6 months after surgery.
B C
A
2.5.2 INTRAMEDULLARY NAILING
Intramedullary fixation was proposed in the 1930s by the Rush brothers (Rush et al. 1950) with a flexible pin. Gerhard Küntscher popularized the technique by developing a more rigid intramedullary implant (Küntscher 1940, 1958).
Intramedullary nailing (IMN) became popular, especially in Northern Finland, where Küntscher served in the German troops during World War II.
Later, an intramedullary bundle nailing technique with several intramedullary pins was introduced (Hackethal 1961), and this technique is today used in, for instance, Morocco, Brazil, Cote d’Ivore, and the Czech Republic (Rodríguez-Merchán 1995, Obruba et al. 2012, Sié et al. 2014, Mohamed et al. 2018). It has not gained popularity in Finland.
The most common method of IMN in Finland is locked nailing, where the nail is introduced to the intramedullary canal of the fractured humerus either from the proximal (antegrade nailing) or distal (retrograde nailing) end of the bone, as described in the exposures for intramedullary nailing above.
The nail is locked from both sides of the fracture with screws. The fracture site is normally left untouched but can be opened in the cases with radial nerve palsy for identification and possible repair of the nerve. The natural benefit of IMN compared to ORIF is less prominent surgical scars as it can be introduced with only small incisions.
The use of IMN in humeral shaft fractures has been studied extensively.
There are several RCTs (Chiu et al. 1997, Chapman et al. 2000, McCormack et al. 2000, Changulani et al. 2007, Putti et al. 2009, Li et al. 2011, C. Wang et al.
2013, Singh et al. 2014, Fan et al. 2015, Akalın et al. 2020) and meta-analyses (Bhandari et al. 2006, Heineman et al. 2010, Kurup et al. 2011, Liu et al. 2013, Ma et al. 2013, Ouyang et al. 2013, X. Wang et al. 2013, Dai et al. 2014, Zarkadis et al. 2018) comparing IMN with ORIF. According to these publications, the outcomes are comparable, except for the higher risk of shoulder pain and reoperation with IMN than with ORIF. The popularity of IMN varies among countries, with less interest than with ORIF in treating traumatic shaft fractures in Finland and the USA (Huttunen et al. 2012, Gottschalk et al. 2016, Schoch et al. 2017). For pathological humeral shaft fractures, IMN has proven to be a valuable tool and is commonly used for this indication in Finland (Flinkkilä et al. 1998, Flinkkilä 2004, Laitinen et al.
2011).
2.5.3 MINIMALLY INVASIVE PLATE OSTEOSYNTHESIS
Minimally invasive plate osteosynthesis (MIPO) has recently gained in popularity (Tetsworth et al. 2018). The principle of using MIPO in humeral shaft fractures was published in 2002 (Fernández Dell’Oca 2002), with reports of case series following thereafter (Livani et al. 2004, Zhiquan et al. 2007, Apivatthakakul et al. 2009). The rationale behind MIPO is to combine the benefits of ORIF and the minimal surgical soft tissue trauma of IMN. The plate
is inserted and attached using two separate small incision without disturbing the fracture site. The major concern has been the possible secondary radial nerve palsy (SRNP), as the plate is introduced without visibility to the nerve (Livani et al. 2009). However, in comparative studies the risk has not proven to be an issue; in fact, the reported incidences of SRNPs are higher with IMN or ORIF in studies comparing MIPO with IMN or ORIF (Beeres et al. 2020, van de Wall et al. 2021). It is noteworthy that in some studies the rate of SRNP after ORIF is unacceptably high (>30%) (An et al. 2010). The RCTs from China, Egypt, Brazil, Korea, and the Czech Republic, with low numbers of participants comparing MIPO with either ORIF or IMN, showed similar outcomes with regard to complications and function (Lian et al. 2013, Benegas et al. 2014, Smejkal et al. 2014, Esmailiejah et al. 2015, Hadhoud et al. 2015, Kim et al. 2015). In Finland, use of MIPO in humeral shaft fractures has not yet gained popularity.
2.5.4 EXTERNAL FIXATION The use of external fixation (Fig. 14) in treatment of humeral shaft fractures was first published in 1907 (Lambotte 1907). The first case series, including 8 cases, was published in 1978 (Kamhin et al.
1978). This was followed by a larger series of 164 patients, where the method was used for complex proximal and distal metaphyseal shaft fractures (Hinsenkamp et al.
1984). More recently, it has been used mainly as a temporary fixation
before definitive treatment with either plate or nail in patients with severe soft tissue injuries or polytrauma (Sarmiento et al. 2001, Suzuki et al. 2010). It has proven to be a valid definitive treatment method in infected nonunions (Bassiony et al. 2009, Xiao et al. 2016), with some authors, many from Italy, recommending it in acute noncomplicated fractures as well (Tartaglia et al.
2016, Basso et al. 2017, Alhammoud et al. 2019, Costa et al. 2019). To date, no RCTs have compared external fixation with other treatment methods in humeral shaft fractures.
In Finland, external fixation is seldom used even in complicated fractures. At Helsinki University Hospital, only 4 of 938 fractures were treated temporarily with this method between 2006 and 2016 (unpublished data).
Fig. 14. Albin Lambotte (1866–1955) performed the first external fixation in 1902.